The band have toured solidly for 18 months since the release of their latest album I'm With You and ahead of headlining Big Day Out (BDO) say they are in top shape.

"For me it's been the most fun touring since the mid 80s," said singer Anthony Kiedis, whose addiction to heroin and crack was documented in his autobiography Scar Tissue.

"It's been a really joyful couple of years being on the road. We've seen a lot of beautiful places and were still carrying that momentum."

As part of their BDO set the Chili Peppers are looking to promote their support of the Sea Shepherd Conservation Society, incorporating their digital art into the band's video backdrop on stage and dedicating each performance to the anti-whaling group.

Kiedis told a media conference in Sydney on Friday he has no problem with Japan as a nation but he hopes the country's whaling fleet goes home empty-handed.

While the Chili Peppers have been reinvigorated by the addition of young guitarist Josh Klinghoffer, a replacement for John Frusciante who quit two years ago, they have clocked up enough years to be considered grand old men of rock.

They've dealt with death, losing original guitarist Hillel Slovak to a drug overdose in 1988, their own drug problems and a revolving door of performers.

For veteran bassist Flea, who celebrated his 50th birthday in October, the band's music will never age but he acknowledges that three decades is a long time to be throwing yourself around the stage.

"Sometimes it honestly does tend to trip me out, not that it's strange because it feels like the same as ever in terns of the hopes and potential that lies ahead.

"But it's funny because I always look back to when we were just little and one of the things that people used to say about us was 'oh they're so young and they've really got a lot of gumption'.

"Relative to the world of music we're not kids anymore but our enthusiasm hasn't dampened one modicum."

Those attending the BDO concerts around Australia have been promised a wide-ranging set, from classics including songs from Blood Sugar Sex Magik and Californication to a David Bowie cover.

Big Day Out travels to the Gold Coast on January 20, Adelaide on January 25, Melbourne on January 26 and Perth on January 28.